Now you can run ~/localperl/bin/perl -v. To use it instead of your system perl you can add ~/localperl/bin to your PATH or set an alias. For all these steps (including download) there is an handy utility: perlbrew.

Let's see it in action ...

This is my system perl:

uwe@quad:~$ perl -v
This is perl, v5.10.1 (*) built for x86_64-linux-gnu-thread-multi
...

Init the perlbrew environment (you have to do this once):

uwe@quad:~$ perlbrew init
Perlbrew environment initiated, required directories are created under
/home/uwe/perl5/perlbrew
Well-done! Congratulations! Please add the following line to the end
of your ~/.bashrc
source /home/uwe/perl5/perlbrew/etc/bashrc
After that, exit this shell, start a new one, and install some fresh
perls:
perlbrew install perl-5.12.1
perlbrew install perl-5.10.1
For further instructions, simply run:
perlbrew
The default help messages will popup and tell you what to do!
Enjoy perlbrew at $HOME!!

Add this line to ~/.bashrc:

uwe@quad:~$ vi ~/.bashrc

Now, install Perl 5.12.2:

uwe@quad:~$ perlbrew install perl-5.12.2
Attempting to load conf from /home/uwe/perl5/perlbrew/Conf.pm
Fetching perl-5.12.2 as /home/uwe/perl5/perlbrew/dists/perl-5.12.2.tar.gz
Installing perl-5.12.2 into /home/uwe/perl5/perlbrew/perls/perl-5.12.2
This could take a while. You can run the following command on another shell to track the status:
tail -f /home/uwe/perl5/perlbrew/build.log
(cd /home/uwe/perl5/perlbrew/build; tar xzf /home/uwe/perl5/perlbrew/dists/perl-5.12.2.tar.gz;cd /home/uwe/perl5/perlbrew/build/perl-5.12.2;rm -f config.sh Policy.sh;sh Configure -de '-Dprefix=/home/uwe/perl5/perlbrew/perls/perl-5.12.2';make;make test && make install) >> '/home/uwe/perl5/perlbrew/build.log' 2>&1
Installed perl-5.12.2 as perl-5.12.2 successfully. Run the following command to switch to it.
perlbrew switch perl-5.12.2

Switch to 5.12.2:

uwe@quad:~$ perlbrew switch perl-5.12.2

Version check :)

uwe@quad:~$ perl -v
This is perl 5, version 12, subversion 2 (v5.12.2) built for x86_64-linux
...